The present invention concerns a novel drip chamber and, more particularly, a drip chamber that is suitable for use in medical administration sets.
Drip chambers are widely used in the administration of liquids to patients. Often the drip chamber is connected at the outlet of a burette or the drip chamber may be connected to the outlet of a container (i.e., bottle or bag) containing parenteral liquid, blood, or any other liquid that is intended to be administered to the patient. Typically the drip chamber assembly includes an inlet connected to a drop former, and a plastic chamber, with the inlet communicating with the inside of the plastic chamber via the drop former. In order to commence the flow of liquid to the patient, the drip chamber is conventionally primed by squeezing the chamber with the first two fingers and the thumb.
It is very desirable that the drip chamber have the ability to be primed easily. To this end, the drip chamber must be sufficiently flexible to enable the operator to prime the chamber easily by squeezing the chamber with the operator's first two fingers and thumb so that a sufficient amount of air can be displaced and liquids can flow into the drip chamber. It would appear that in order to make priming easier, a drip chamber having a thinner or more flexible wall would be desirable. However, by decreasing the thickness of the wall and by making it more flexible, it has been found that the chamber might collapse under a negative pressure condition and air might become aspirated to the patient.
It is, therefore, an object of the invention to provide a drip chamber that yields to priming easily but that will not callapse under a negative pressure condition, such as when restriction is added to the inlet port.
It is a further object of the present invention to provide a drip chamber that is relatively flexible but non-collapsible under a negative pressure condition, and that is simple in construction and easy to manufacture.
Other objects and advantages of the present invention will become apparent as the description proceeds.